As known, universal serial bus connectors (hereinafter referred as USB connectors) are electrical connectors widely used in diversified electronic devices such as personal computers, notebook computers, personal digital assistants (PDAs), multimedia players, portable hard disc drives, power supply apparatuses, or the like. USB (Universal Serial Bus) is a specification to establish communication between a USB host device and a USB peripheral device. Generally, the USB connectors may be classified into two types, i.e. USB sockets and USB plugs. The host device that provides electricity has a USB socket, and the USB peripheral device has a USB plug. In other words, the USB socket may be used as a power socket. Through the USB socket, the host device may provide electricity to the external peripheral device or charge a chargeable battery within the external peripheral device.
For example, an external peripheral device such as a mobile phone, a notebook computer or a personal digital assistant may be powered by common chargers. In addition, the external peripheral device may be electrically connected with a host device (e.g. a personal computer, a power supply or a power adapter) having a USB socket through a USB cable in order to receive electricity from the host device.
The use of the conventional USB socket, however, still has some drawbacks. For example, even if no mating electric connector (i.e. a USB plug) is inserted into the USB socket or the electronic device with the USB socket is in a no-load condition, electricity is still transmitted to the USB socket. Under this circumstance, the power consumption is increased, the operating efficiency is decreased, and the USB socket fails to meet the power-saving requirement. For solving these drawbacks, an additional mechanical switch is used for switching the on/off statuses of the USB socket. As known, the mechanical switch has complicated configurations and increased fabricating cost. In addition, the use of the mechanical switch is detrimental to space utilization and miniaturization of the electrical connector. Since the transmission of the electrical power through the USB socket is controlled by manually adjusting the mechanical switch, this controlling approach is not user-friendly.